1. First Department of Obstetrics and Gynecology, Maternal-Fetal Medicine Unit, National and Kapodistrian University of Athens, Alexandra Maternity Hospital Athens, Greece
2. Center of Mother and Child, Philipps University of Marburg, Baldingerstrasse, 35032 Marburg, Germany
3. Clara Angela Foundation, Berlin, Germany
4. Preterm Birth Prevention Clinic, High-Risk Pregnancy Unit, Maternal-Foetal Medicine, Department of Obstetrics and Gynaecology, Hospital Universitari Vall d’Hebron, Vall d’Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona (UAB), Barcelona., Spain